A remote terminal unit (RTU) represents a device or system that provides localized control and data access at a site that is remote from a supervisory control and data acquisition (SCADA) system or other automation system. For example, multiple RTUs can be used at different sites and for different purposes in an oil and gas field. The RTUs can collect data, perform local control using sensors and actuators at different sites (such as wells, pipelines, and compression stations), record historical values, and provide live and historical data to a SCADA system. The SCADA system can execute control logic and alter the operations of actuators at the different sites via the RTUs. The RTUs themselves could also incorporate algorithms for data analytics.